如何在结构数组的末尾添加结构？

Question

我有一个动态分配的结构数组。我想在数组的末尾添加新的结构。

结构定义为

ddate1, ddate2, ddate3

数组定义为

struct book
{
    char *id;
    char *bookName;
    char *authorName;
    char *numOfPages;
    char *publishingYear;
    char *category;
} typedef t_book;

Answer 1

使用realloc()

重新分配内存

size_t new_book_count = book_count + 1;
//                              size of 1 book * book count
void *newbooks = realloc(books, sizeof *books * new_book_count);
// Successful ?
if (newbooks == NULL) {
  perror("Out of memory");
  return error;
}
books = newbooks;
// copy in new structure
books[book_count] = new_struct;
book_count = new_book_count;

Answer 2

做这样的事情

t_book* books;
books = malloc( 4 * sizeof *books); //Preferred way to do malloc
//At this point you want to add one in the end
t_book* bookstemp=realloc(books,5 * sizeof *books);
// temporary variable for the case where realloc fails not to loose data
if(bookstemp){
  printf("Realloc succeeded\n");
  books=bookstemp;
}
else
  printf("Realloc failed\n");